Residents across Catalonia anticipate a particularly severe allergy season. A combination of a wet winter and a warm spring has created a perfect storm for pollen production. Experts warn that recent abundant rainfall has supercharged plant growth, resulting in more intense, prolonged flowering that will significantly impact the region’s 1.5 million allergy sufferers.

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The forecast comes from the Aerobiological Network of Catalonia (XAC), which monitors airborne particles like pollen. In their spring outlook, published by the Institute of Environmental Science and Technology (ICTA-UAB) at the Autonomous University of Barcelona (UAB), researchers explain a seemingly paradoxical situation. While rain temporarily clears pollen from the air, sustained precipitation throughout what has been dubbed the rainiest winter in Catalonia for 30 years has deeply nourished the soil and strengthened the vegetation.

Consequently, healthier, more robust trees and plants are now poised to release exceptionally high concentrations of pollen. Later-pollinating species this year, such as cypress and ash, have already surpassed historical averages recorded since 1994.

The Paradox of the Rain

Jordina Belmonte, a botanist and head of the XAC, explained the dynamic. “Although all this rain may have washed a lot of pollen to the ground, it has also created very strong trees that will produce a lot of flowers because they will be well-watered,” she noted. These conditions will particularly affect the pollination of plane trees, olive trees, and various grasses, prolonging the season and complicating daily life for those with respiratory allergies.

The effects are already evident in specific areas. For instance, the Bages region saw a “sudden increase in cases between mid-February and early March,” according to a report in Diari Catalunya, highlighting the localised intensity of the phenomenon. Similar patterns of wet, warm weather creating health and environmental challenges have also been observed elsewhere, with Tarragona recently reporting a surge in pest infestations under similar conditions.

However, Belmonte added a note of caution, explaining that the outlook could change. “If the heavy rainfall we’ve seen since the start of the year continues, it would continue to clean the atmosphere and wash the pollen away,” she said. The forecast for a wetter-than-usual March could either help clear the air or, if combined with high temperatures, simply accelerate and shorten the pollination cycle for some plants.

A Growing Public Health Concern

The increased pollen load carries significant public health implications. According to data from the Catalan Society of Allergology and Clinical Immunology (SCAIC), approximately 25% of Catalonia’s population suffers from allergic rhinitis, and up to 12% from allergic asthma.

Dr. Gaspar Dalmau, president of the SCAIC, emphasised the growing challenge from climate change, which alters pollination patterns, lengthens exposure periods and increases the concentration of allergens. “This impacts health and causes more visits to emergency rooms,” he explained, underscoring the importance of prevention and monitoring.

“Diagnosis and prevention are important to effectively manage patients, enabling them to lead a more normal life,” Dr. Dalmau stated, as reported by Ara Cat.

In response, experts advise those affected to take proactive measures. They recommend wearing masks and sunglasses outdoors to limit exposure. Additionally, the XAC publishes weekly pollen forecasts on its website, a vital tool for residents to plan activities and manage symptoms. “It helps you know if the place you plan to go for the weekend, for example, might be problematic for your particular allergy,” Belmonte concluded.